The purpose of this research is to determine the nature of the enzymatic mechanisms responsible for the biosynthesis of O-alkyl and O-alk-l-enyl ether bonds in glycerolpids, which are prevalent in cancer cells. The problem is being approached from the point of view of characterizing the properties of the membrane-bound enzymes, including attempts at solubilization and purification. The enzymatic properties of the enzymes are being evaluated by chemical, physical, kinetic, and immunological techniques. These studies also include the investigation of specific inhibitors (analogs of precursors) of key enzymes involved in the metabolism of ether lipids. An ultimate goal is to purify alkyl synthase and Delta 1 alkyl desaturase. We plan to determine whether peroxisomes in tumors also contain the enzymes for synthesizing ether lipids, since peroxisomes have been reported to possess these biosynthetic activities in some tissues. Experiments will be initiated to test a series of inhibitors for alkyl synthase; the inhibitors to be used are structurally related to acyldihydroxyacetonephosphate, the precursor of alkyldihydroxyacetone-P. Experiments in progress are determining whether the nature of the acyl group at the sn-2 position of 1-alkyl-2-acyl-sn-glycero-3-phosphocholine influences the specificity of alkyl desaturase in the biosynthesis of plasmalogens. Properties of acyl-CoA reductase and NAD ion:fatty alcohol oxidoreductase will also be characterized and attempts will be made to solubilize and purify these enzymes from microsomes. The role of a phospholipid requirement for the PTe-H4-dependent alkyl monooxygenase cleavage enzyme is also being evaluated.